Electromagnetic controlling means



y 1940. w. J. GARLICK, JR 2,207,248

ELECTROMAGNETIC CONTROLLING MEANS Filed June 1, 1938 2 Sheets-Sheet lATTORNEY July 9, 1940. w. J. GARLICK, JR 2,297,243

ELECTROMAGNETIC CONTROLLING MEANS Filed June 1, 1938 2 Sheets-Sheet 2OUTPUT l/JV' NVENTOR P J gar i'oui.

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ATTORNEY Patented July 9, 1940 ELECTROMAGNETIC CONTROLLING MEANS WalterJ. Garlick. Jr., Glen Ridge, N. J., assignmto American Transformer Compay, Newark,

Application June 1, 1938, Serial No. 211,279

9 Claims.

which the said means may be associated.

In order to illustrate the application of my im- 5 proved type 01electromagnetic controlling means,

I have chosen to illustrate it as applied to controlling the voltage 01'the output side of an alternating current voltage regulating mechanismwherein the voltage of this output circuit must be regulated or held ata constant value; for example, within the fraction of a volt, eventhough the input side may have a variation voltage of as much as 25% oreven higher.

Where the output voltage from the regulator is to be held to within afraction of a volt variation, it will be seen that the control means forthe regulator must be not only very sensitive but accurate and capableof continuous use over a long period of time. To obtain this sensitiveand reliable operation, I prefer to use, as a part of theelectromagnetic control means, an instrument somewhat like an A. C.voltmeter with a suppressed zero, in which the moving element isrestored by a spring and is proportional to the root mean square valueof the current flowing through the instrument. By using such aninstrument with a suppressed zero, the scale may read, for example for a-volt output circuit, from 109 to 111 volts. Associated with thisinstrument is another part of the electromagnetic control means whichcomprises a structure having a core of magnetic material and windingsthereon, all of which cooperate with the said instrument to provide thenecessary control on the voltage regulator per se.

apparatus with which it is used.

Other and ancillary objects will be discerned by one skilled in thisart, from a reading of the specification taken in connection with theannexed drawings, wherein:

Figure 1 is a diagram to illustrate some of the fundamental principlesinvolved in my invention. Figure 2 is a diagram further illustrating thedifferent principles involved.

Figure 3 is an other diagrammatic illustration showing another form ofmyinvention.

Figure 4 is a still further modified form illustrating certainprinciples involved in my invention.

Figure 5 shows a further modified form of con struction.

Figure 6 is a view on the line e-s of Figure 5.

Figure '7 is a diagrammatic illustration showing the application of myinvention to a certain type of voltage regulating apparatus.

Since Figures 1 to 6 inclusive will probably be better understood aftera description of Figure 7, a the last will be described first in detail.In Figure 7, T illustrates a voltage regulating device based onSchermerhorn Patent 2,089,434, in which I is an exciting windingarranged on the core of the regulator. The core also carries windings 2and 3, each of which has a commutator surface on which brushes operate.The brushes are carried by a connecting bar t which in turn is mountedon a threaded shaft 5 geared to a motor M through gears 6 and 1. Oneside of the motor armature is connected to one side of the outputcircuit to be regulated through the wire 8. The other side of the motoris connected by wire 9 to the central point of the field I0 01 the motorM.

One end of the field III is connected to the plate ll of a rectifiertube l2 having a grid 13 and a filament H. The other end of the fieldwinding I0 is connected to the plate l6 of a tube ll, similar to thetube l2. The tube I I has a grid l8 and a filament l9. The filaments l4and I9 are connected to a secondary winding 20 of a transformer, theprimary of which is connected by leads 22 and 23 to the output circuitof the regulator. Connected to the leads 22 and 23 is the coil of aninstrument 24 which is preferably of the iron vane type. The moving partof the instrument 24 is illustrated as having a shaft 25 operatedbetween the stops 26 and 21 and carrying a short-circuited winding 28which may be a single short-circuited turn or a plurality ofshort-circuited turns. The member 28 is normally positioned, when thereis no change in voltage in the output circuit, in an air gap 29 betweenthe core member 30 and another core member 3| forming part of a magneticstructure E.

The core member 3| is connected by legs 32 and 33, and arms 34 and 35 tothe core member 30, thereby completing one form of magnetic structure.That part of the core 30 which carries the winding 36 is connectedacross the output circuit. The core legs 32 and 33 carry interconnectedwindings 31 and 38 which are connected at their central point 39 and byway of a lead 40 to a hold-oil bias device 4|. The free end of thewinding 31 is connected through a gridcurrent-limiting resistance R1 tothe grid I3 of the tube l2, while the free end 01' the winding 38 isconnected through the grid-current-limiting resistance R2 to the gridiii of the tube ll. The device 4! is connected across the output circuitof the regulator as indicated and also has a connection to the centralpoint of the filament trans=- former winding 20. The central point ofthis winding is also connected by the lead 42 to the opposite side ofthe output circuit from the lead 8 running to the motor. A smallcondenser c is bridged across the armature of the motor M to absorb anysparking at the brushes thereof.

In the operation of the circuit diagram shown in Figure 7, it will beunderstood that the wind ings 31 and 38 which are connected in seriesare so wound that the fluxes generated in the legs 32 and 33 are inopposition, and when the output voltage is unvarying the coil 28 will bein a neutral position as indicated. Should the voltage on the outputcircuit change, this is transmitted by the instrument 26 through theshaft 25 and the short-circuited turn 28 will be shifted in the air gap29 either to the right or left, depending on the change in the outputvoltage, and one of the windings 31 or 38 will generate a higher voltagethan the other and thereby excite either the grid l3 or it of the. tubesl2 and ll accordingly; and current will then pass through the motorarmature and through one portion of the field l0 and the proper tube 62or ii, through the plate circuit thereof, and by the conductor 12 backto the output side on the circuit. The motor M will then operate to movethe brushes on the windings 2 and 3 through the bar d of the regulator Tto correct the change in voltage in the output circuit.

The tubes l2 and ill are of the gas-filled type so that they will alsorespond to a shift in the phase of the current applied to their grids,as well as to the voltage. The hold-off bias it, if used, allows a smallamount of plate current to flow through the tubes 82 and il when thecontrol means is in a balanced condition as indicated in Figure 7, theobject being to have a certain amount of excitation in the motor so thatthe operation of the control means, comprising the magnetic structurewith its windings and the instrument will give a quicker and moresensitiye change in the motor circuit.

In Figures 5 and 6 I have shown a different type of magnetic structure,in which the core members 13 and id are connected by a yoke member 65.The core members 33 and id carry windings 15 and l'a which are connectedin series and across the output circuit, and correspond to the singlewinding 35 of Figure 7. The shortcircuited turn 28 is positioned in anair gap 29 and is looped around a portion of the core member carrying awinding generally referred to as as but which corresponds to thewindings and 38 of Figure '7. In this case, the short circuited turn 25is rotated by the shaft 25 instead of swinging as in Figure 7, but thegeneral oper-v ation of the structure is substantially the same as thatdescribed in Figure 7.

In Figure 4 the windings 3V and 38 are arranged on a magnetic member 5bwhich, while shown in open circuit, is preferably in a closed circuit asin Figure 7. A short-circuited turn 28 is shown in displaced position inthe air gap 29. The windings on the core members 56 and 52 correspond tothe windings 26 and ll in the structure shown in Figures 5 and 6.

Another form which the magnetic structure E may take is shown in Figure3, in which the core member 55 is split in two portions 55a and 5%,

but the core members 5| and 52 and their respective windings 46 and 41remain as in Figure 4. In both Figures 3 and 4 the free ends of thewindings 31 and 38 are adapted to be connected to grids of tubescorresponding to l2 and I1 in Figure 7, while their common junctionpoint is connected by a lead 45 to the device 4!. In Figure 3, themoving system between the core members comprises a solid iron vane 53carried on the shaft 25 connected to the instrument 24.

In Figure 2 the core members 54 and 55 carry windings corresponding towindings 46 and 41; likewise the core members 56 and 51 carry similarwindings. In the air gap 29 between these core members there ispositioned a magnetic shunt 58 pivotally mounted on the shaft 25, alongwith a coil 59 carrying two windings corresponding to the windings 37and 58, which windings are connected by the common junction wire 40 tothe device 4! as in Figure '7.

In Figure 1 the coil 59 is similar to that shown in Figure 2, but ispivoted to rotate with the shaft 25 between the magnetic core members 60and GI.

Referring to the somewhat diagrammatic illus trations of Figures 1, 2, 3and 4, it is to be understood that thecore members outside of the airgap 29 preferably have closed magnetic circuits.

Figures 1 to 4 inclusive illustrate different forms which the magneticstructure E may take for the voltage regulator arrangement shown inFigure '7, but I prefer to use the form of structure shown in Figure 5or Figure 7.

While the electromagnetic controlling means which I have describedprovides excellent and close regulation in an electrical circuitarrangement, such as shown in Figure 'l, I do not wish to be undulylimited in the application to which my invention may be put, as theinstrument 24 may be actuated by other means than the output circuit ofthe regulating system shown and described, or the short-circuitedwinding in the air gap 29 of the electromagnetic structure E may respondto the movement of another instrument equivalent to a voltmeter orinstrument 2%, and it will therefore be obvious that various changes maybe made in the details without departing from the spirit of my inventionor the scope of the appended claims.

What I claim is:

1. Electromagnetic controlling means including a structure of magneticmaterial having a gap in a portion thereof, a short-circuited conductorpositioned around a part of the magnetic structure and located in saidgap, an exciting winding on the magnetic structure for sending fluxthrough the gap in which the short-circuited conductor is located,windings on another part of said structure around which saidshort-circuited conductor is located, said last-mentioned windings beingconnected so the fluxes set up thereby are in opposition, the saidwindings adapted to be connected to devices sensitive to changes such aspotential, phase relation or a combination of both potential and phase,for example the grids of control tubes, and a voltmeter connected acrossa circuit to be controlled, the moving element of the meter having amember carrying said short-circuited coil for moving the same to changethe potential in said last-mentioned windings for the purpose described.

2. An electromagnetic control means including a magnetic core structurehaving an air gap in a portion thereof, a winding on a portion of thecore structure for normally sending magnetic flux through said air gap,a short-circuited winding located in said air gap, other windings onother parts of said core structure and connected so as to neutralizeeach other when said winding located in the air gap is in a neutralposition, but one of said other windings being capable of generating ahigher potential than the other winding of said last-mentioned windingswhen the gap coil is moved out of neutral position, and an instrumentresponsive to changes that are to be regulated forming part of saidcontrol means for moving said gap winding to cause a shift of flux inthe magnetic structure via the air gap so one of said other windingsdevelops a higher potential and phase shift than its companion windingfor acting on a regulating mechanism.

3. An electromagnetic control means including a magnetic core structurehaving an air gap in a portion thereof, a winding on a portion of thecore structure for normally sending magnetic flux through said air gap,a member movably mounted in the air gap and being capable of changingthe flow of flux through the air gap, windings associated with saidmovable gap member so as to generate a voltage in the windings capableofacting on a regulating mechanism, and an instrument connected to movesaid movable gap member, said instrument forming part of said controlmeans and being responsive to changes that are to be regulated.

4. Translating means for converting changes, such as voltage variationsin an electrical output circuit, into electromechanical work to regulatesaid changes, said translating means including a magnetic core structurehaving an air gap in a portion thereof, a winding on a portion of thecore structure for normally sending magnetic flux through said air gap,a member movably mounted in the air gap and being capable of changingthe flow of iiux through the gap, windings positioned on the core so asto have a voltage generated therein when said member moves in the airgap, means connected to said last-mentioned windings and responsive tosaid voltage changes therein for causing an electromechanical mechanisminter-connected between an input circuit and said output to move tocorrect changes in voltage in the output circuit, and an instru mentelectrically connected to said output circuit and responsive to thevoltage changes therein nd comprising part of said translating means andconnected so as to move said member in the air gap.

5. Translating means for converting changes, such as voltage variationsin an electrical output circuit, into electromechanical work to regulatesaid changes, said translating means including a magnetic core structurehaving an air gap in a portion thereof, a winding on a portion of thecore structure for normally sending magnetic flux through said air gap,a member movably mounted in the air gap and being capable of changingthe flow of flux through the gap, windings positioned on the core so asto have a voltage generated therein when said member moves in the airgap, electronic tubes preferably of the gasfilled type having theirrespective grids connected to said last-mentioned windings which have acommon connection to one side of the output circuit, a motor having itsfield winding connected to the plates of said tubes while the filamentsthereof are connected to one side of the output circuit, the oppositeside of which is connected to the center of the motor field windingthrough the motor armature; a voltage regulator operated by the motorinter-connected between an input circuit and the output circuit, and aninstrument electrically connected to said output circuit and responsiveto the voltage changes therein and comprising part of said translatingmeans and connected so as to move said member in the air gap.

6. Translating means for converting changes, such as voltage variationsin an electrical output circuit, into electromechanical work to regulatesaid changes, said translating means including a magnetic core structurehaving an air gap in a portion thereof, a winding on a portion of thecore structure for normally sending magnetic flux through said air gap,a short-circuited winding positioned in said gap and an instrumentforming part of said translating means and having a part moved by awinding of the instrument and mechanically carrying said short-circuitedwinding, said instrument winding being electrically connected andresponsive to changes in voltage in said output circuit, windingspositioned on the core structure so as to have voltages set up thereinwhen said winding in the air gap is moved by said instrument-movablepart, an electromechanical mechanism interconnected between an inputcircuit and said output circuit, and means, connected to the windings onthe core structure and responsive to the voltages set up therein onmovement of the gap winding, for causing said electromechanicalmechanism to move to correct changes in the voltage in said outputcircuit.

7. Electromagnetic control means for the purpose described comprising, amagnetic core structure having an air gap in a portion thereof, anexciting winding on the core for sending flux through said gap, amovable member positioned in said air gap, an instrument having amovable part mechanically connected to said member in the air gap, saidinstrument having a winding for moving said part and the winding beingconnected and responsive to voltage changes in a circuit whose voltageis to be regulated, a regulator of the type described to regulate thevoltage of an output circuit connected to the regulator, means capableof operating the regulator, and windings associated with the corestructure so movement of said member in the air gap will cause voltagesto be set up in these windings, the terminals of which are connected tosaid regulator operating means.

8. Electromagnetic control means for the purpose described comprising, amagnetic core structure having an air gap in a portion thereof, anexciting winding on the core for sending flux through said gap, amovable member positioned in said air gap, means for moving said memberin the air gap, said means being responsive to changes in a mechanismWhose changes are to be regulated, a regulator to regulate the changesin said mechanism, means capable of operating the regulator, andwindings associated with said core structure so movement of said memberin the air gap will cause voltages to be set up in these windings, theterminals of which are connected to said regulator operating means;

9. Translating means for converting changes, such as voltage variationsin an electrical output circuit, into electromechanical work to regulatesaid changes, said translating means including a magnetic core structurehaving an air gap in a portion thereof, a winding on a portoion of thecore structure for normally sending magnetic flux through said air gap,a member movably mounted in the air gap and being capable of to one sideof the output circuit, the opposite side v of which is connected to thecenter of the motor fieldwinding through the motorarmature, said tubesbeing of a type'which will normally pass a small amount of currentthrough their plate circuits and thereby excite the field of the motorto a certain degree for the purpose described. a-

voltage regulator operated by the motor interconnected between an inputcircuit andthe out put circuit; and an instrument electrically connectedto said output circuit and responsive to the voltage changes therein andcomprising part of said translating means and connected so as to 10.move saidmember in the air gap.

WALTm J. GARLICK,. JR.

